I've recently moved to the other side of the WGB but IIRC Fed Trail still terminates at Millers Rd.
The most direct route would probably be to go left on Millers then right on Francis and follow it all the way down to Hyde St, picking up the bike path from there. It depends on how confident you are amongst traffic though. Being a truck route, Francis St can be intimidating at times and space for bikes is limited - especially when the "full moon" drivers are out and about.
After a number of particularly close shaves, I refused to use Francis St unless I really had to. Instead I took the "scenic" route - right on Millers, under the freeway, left on Clematis Ave, then Kyle Rd, Blackshaws Rd, New St, Brunel St, Montgomery Crs, then Hudson Rd down through Spotswood. Certainly a more convoluted route but one with far less angst.